1. Field of the Invention
The present invention is directed to the field of solar heaters and more particularly to solar convection/conduction fluid heating systems used to augment conventional forced air heating systems or hot water radiator heating systems used to heat homes, offices and other buildings and especially to such systems that magnify solar energy to heat a material acting as a heat sink, such as a stainless steel plate, and wherein air or liquid is conveyed in heat exchange relationship with the heat sink before being conveyed into an air duct or radiator system within a structure to be heated.
2. Brief Description of the Related Art
Due to the need to find alternative sources of energy to reduce the use and consumption of energy sources such as oil, gas and electricity to provide heat for home and other building heating systems, there have been proposed systems which use solar energy to heat liquids and solids in order to provide heat which may be used to directly or indirectly heat homes and other structures. In order to increase the efficient use of solar energy, it has been proposed to use magnification devices to concentrate solar energy toward a pipe or other conduit through which a fluid medium, such as water, is being conveyed to heat the fluid before the fluid is pumped or otherwise conveyed into an area to be heated by convective heat exchange of the air with the area such as an interior room of a home. In a like manner, it has been proposed to use magnification devices to concentrate solar energy onto a solid material in order to heat the material so as to function as a heat sink to heat air or a liquid passing in heat exchange relationship with the heat sink material to heat the air or liquid by convective or conductive heat exchange.
U.S. Pat. No. 5,915,376 to McLean teaches the use of a Fresnel lens mounted within an outer dome wherein a heat sink material is heated by concentrating solar energy passing through the Fresnel lens onto the heat sink material so as to heat fluid passing in heat exchange relationship with the heat sink material. U.S. Pat. No. 4,258,698 to Sales shows a somewhat similar solar heater using a Fresnel lens to concentrate solar energy to heat a heat sink material.
U.S. Pat. Nos. 6,384,320 and 6,653,551, both to Chen, teach the use of a Fresnel lens with a solar collector wherein solar energy from the Fresnel lens is directed to a conduit through which a liquid is flowing in order to heat the liquid. U.S. Pat. No. 7,946,286 to Raymond et al teaches a roof mounted solar energy heater having a plurality of Fresnel lenses for directing solar energy toward a heat sink tube through which a fluid is flowing in order to heat the fluid.
U.S. Pat. No. 8,235,034 to Flaherty teaches a solar heater having a structure to heat both air and water for a house or other building which uses flow controllers and the like to control the circulation of the heat exchange fluid being heated by the solar energy. U.S. Pat. No. 4,026,267 to Coleman et al teaches a solar heater connected to an air duct of a conventional heating system wherein solar energy is concentrated through lenses to heat fins that are in heat exchange relationship with a flow of air or other fluid.
To further increase the efficiency of solar heaters, it has also been proposed to mount solar energy concentrators, such as Fresnel lenses, such that the lenses track the sun both as the earth rotates relative to the sun daily from east to the west and such that the lenses also remain aligned with the sun as the angle of the earth relative to the sun changes during a year, such as taught in the aforementioned patents to McLean and Raymond et al.
There remains a need to further increase the efficiency and operating characteristics of Fresnel lens type solar heaters to augment conventional home and other building forced air and liquid heating systems so as to make better use of solar energy systems and reduce the use of conventional energy sources such as oil, natural gas and electricity.